SOUTH WAZIRISTAN, Pakistan (Reuters) - This Christmas, pastor Nazir Alam will stoke up a fire, lay a fresh cloth on the altar and welcome parishioners as they arrive at his church in Waziristan, a Pakistani tribal area known as an al-Qaeda haven. "The lights are all up, and the choir boys are ready. The church is looking its best," said 60-year-old Alam, a former missionary who has celebrated his last ten Christmases there. "There's not much left to do but to pray and rejoice." Outsiders might see little cause for joy. ...